Harrison, a five-time Pro Bowler and 2008 NFL Defensive Player of the Year, was the heart and soul of the Steelers defense.

His 64 career sacks are fourth in franchise history, according to the Pittsburgh Post-Gazette, but Harrison's impact went beyond the stat sheet.

To the 31 NFL teams outside of Pittsburgh, Harrison was a villain. Fines for illegal hits, which amounted to $125,000 in 2010, were the cost of doing business.

Harrison brandished two guns on the cover of Men's Journal during the summer of 2011. In the article titled "Confessions of an NFL Hitman," Harrison ripped NFL commissioner Roger Goodell, calling him a "punk," a "puppet," and other things that can't be printed.

And that was before Harrison became the first player to be suspended for a helmet-to-helmet hit when he knocked out Browns quarterback Colt McCoy in December of 2011.

The Steelers defense becomes too civilized without Harrison.

Sure, Harrison will be 35 next season, and he's missed eight games over the past two years because of injuries. With so little room under the salary cap, the Steelers weren't going to pay Harrison $6.57 million. They asked him to take a pay cut, and the two sides couldn't come to an agreement.

Now, the Steelers are without the menacing persona that has been an element in all of their championships.

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Harrison backed up Joey Porter, his predecessor as the Steelers' requisite bad boy, in 2005.

Porter called the Indianapolis Colts "soft," according to the Pittsburgh Post-Gazette, before the Steelers played them in the 2005 AFC Divisional Playoffs. Then he and the Steelers backed up those words by stunning the Colts on their way to winning Super Bowl XL.

Legend has it that Porter tried to get Ray Lewis to come off the Ravens' team bus so he could fight him after a game against them in 2003, and this was a week after Porter was shot in the thigh.

Porter denied that report by ESPN's Chris Mortensen, according to the Pittsburgh Post-Gazette, but the story will live on in myth.

Before Porter in the Steelers' lineage of thuggery was Greg Lloyd.

Like Harrison, Lloyd was a linebacker who used ferocity to overcome a lack of size. Like Harrison, Lloyd was fined for rough play, including a $12,000 levy for knocking Brett Favre out of a preseason game. At the time, according to SI Vault, it was the biggest fine in NFL history.

Even though Lloyd never won a Super Bowl ring, he did play in a Super Bowl and dropped an F-Bomb on national TV after the Steelers defeated the Colts in the 1995 AFC Championship Game.

If there was a Steelers Bad-Ass Bible, Mean Joe Greene's bio would be the Book of Genesis.

Greene was ejected from two games as a rookie, according to SI Vault. He challenged Dick Butkus to a fight during a game, and Butkus walked away. He complained that opponents got away too many times with holding him.

Harrison, who had a similar plight, would have fit right in with those Steelers defenses of the 1970s.

So who's going to bring the mean to the Steelers defense now?

Will the Steelers defense be weaker without James Harrison?

YesNoIt won't change much either way.Submit Votevote to see results

Will the Steelers defense be weaker without James Harrison?

Yes

47.1%

No

26.6%

It won't change much either way.

26.4%

Total votes: 1,738

Troy Polamalu was the 2010 NFL Defensive Player of the Year, so he can match Harrison in that regard. But unlike Harrison there doesn't appear to be a mean bone in his body.

Ryan Clark? An argument can be made that he's currently the Steelers' best defensive player, and he's written some checks to the commissioner's office for his hits. But Clark will turn 34 next season, and he's becoming awfully comfortable with a microphone in his hand.

It's all well and good to studiously execute the Xs and Os of Dick LeBeau's defense, but the Steelers need a player who puts a lump in the throat of opposing offenses.

After forcing 35 turnovers and winning the AFC championship in 2010, the Steelers forced just 35 in 2011 and 2012 combined. One factor in that paucity of takeaways over the past two seasons is the fact that Harrison hasn't been on the field as much.